Extends specified farm housing programs of the Farmers Home Administration under the Housing Act of 1949. Authorizes appropriations for fiscal year 1980 for: (1) loans and grants for repairs or improvements of rural dwellings and financial assistance to provide low-rent housing for domestic farm labor; (2) loans and grants for mutual and self-help housing programs in rural areas and small towns; (3) the Self-Help Housing Land Development Fund; and (4) grants for the development of technical and supervisory assistance programs in rural areas with Federal, State, and local housing programs for low-income families. Extends through fiscal year 1981 the authority of the Secretary of Agriculture to insure loans which provide rental and cooperative housing for the elderly or others of low-and moderate-incomes and to insure and make loans for housing and buildings on farms owned by low-or moderate-income families. Permits the Secretary to make or insure loans for 40 percent of the units in multifamily cooperative or rental housing projects. Authorizes appropriations for fiscal year 1981 of such sums as may be necessary to carry out programs and activities for which appropriations for the fiscal year 1980 are authorized by this Act.